1. Field of the Invention
Devices, systems, and methods consistent with the invention relate to an automatic feed adjuster.
2. Description of the Related Art
In the related art, there are various types of welding processes, including processes which utilize a continuous wire feed as a welding electrode.
A diagrammatical representation of such a related art continuous wire feed welding process is illustrated in FIG. 1. In FIG. 1, a welding system 1 includes a control circuit 10, a power source 20, a motor 12, and spool 30. Spool 30 contains wire 35 spooled thereon. Motor 12 drives opposing rollers 14 to take up wire 35 from spool 30 and send it to gun 22. The operator utilizes gun 22 to form a weld on workpiece 40. As the weld is formed on workpiece 40, wire 35 is consumed at gun 22, and is replaced by feeding more wire 35 to gun 22 by action of motor 12 and rollers 14 at a constant rate.
Different types of wires 35 are available for different welding applications. The selection of a particular type of wire depends on several factors, including, e.g., the type of material being welded, the weld design, material surface conditions, quality concerns, and process variation concerns. Due to these considerations, the different types of wires have widely varying diameters.
As mentioned above, in the system illustrated in FIG. 1, wire 35 is fed to gun 22 at a constant rate during a welding operation. This rate is set by the operator via a variable knob on control circuit 10 before the welding operation begins. Different rates are appropriate for different welding applications. For example, a thicker material to be welded may require a faster feed, while a thinner material may require a slower speed to avoid burn-through.
In order to provide the desired feed rate, an amount of tension between rollers 14 is also adjustable by the operator, before the welding operation begins. The term tension is broadly utilized in this context to represent both a “tension” force acting on each roller 14 in a direction toward the other (e.g., as created by a spring member connecting the two rollers 14) and as a “pressure” forcing the rollers 14 toward each other (e.g., as created by spring members on opposite sides of the two rollers 14). This tension between rollers 14 acts to draw wire 35 off of spool 30, and feed wire 35 toward gun 22. The adjustment is typically provided by a small thumb-wheel or other adjustment mechanism.
The tension between rollers 14 is set in view of the diameter of the wire 35, and remains constant during the welding operation. Unfortunately, if the tension between rollers 14 is set too high, the rollers 14 will deform the wire 35 as it passes therethrough. Such a deformed wire 35 can jam gun 22. On the other hand, if the pressure between rollers 14 is set too low, wire 35 will be fed to gun 22 at an erratic rate, which results in an erratic welding arc and poor weld quality.
Further, even if the tension is set properly on a first section of wire 35, there is inherent variability in the diameter of wire 35 due to such factors as manufacturing process variation and/or damage during shipment or storage. In other words, wire 35 may not have a constant diameter along its length. Thus, as wire 35 is fed to gun 22 through rollers 14, the tension set before the welding operation (in view of a beginning diameter of wire 35) might become inappropriate, and wire 35 might begin to deform or be erratically fed, as described above.
The above problems demand an improvement in the related art system.